Pergolide is an ergoline derivative which exhibits potent dopaminergic agonist activity and also decreases plasma prolactin concentrations. The compound is thus useful in treating physiological manifestations associated with hyperprolactinemia. Chemically, pergolide is D-6-n-propyl-8.beta.-methylmercaptomethylergoline.
Pergolide is known to decompose upon exposure to light (apparently to a sulfoxide species) thus making it necessary to handle the compound and store the ultimate dosage form in light-controlled environments so as to avoid a demonstrable drop in potency of the therapeutic agent. In order to retard this drop in potency, certain stabilizing agents have been incorporated into pharmaceutical compositions containing pergolide which surprisingly reduce the decomposition of this compound when exposed to light.